The haemostatic effects of the Chinese herbal drug Yunnan Bai Yao: a pilot study

The effects of Yunnan Bai Yao on the bleeding time in rats and the blood clotting time in rabbits and man were studied. The medicinal preparation markedly shortened both the bleeding and clotting times; the decreases were significantly more intense than those inconsistently produced by starch or by starch with calcium. These preliminary findings suggest that the action of Yunnan Bai Yao appears not to be due to its pH (5.2) or to vasoconstriction, but other factors such as its calcium content or the physical effect of its particle size cannot yet be excluded.